TENSION-COMPRESSION FATIGUE BEHAVIOR OF A SILICON-CARBIDE CALCIUM-ALUMINOSILICATE CERAMIC-MATRIX COMPOSITE

The fatigue behavior of a silicon carbide fiber reinforced glass ceram ic matrix composite, SiC/CAS subjected to tension-compression cycling was investigated. Two laminate layups were studied: cross-ply, [0/90]2 S and unidirectional, [0]16. At first, the fatigue limit based on one million cycles was established for a tension-tension fatigue condition . Then, compression cycling was superimposed on this measured fatigue limit. The addition of this compression loading resulted in the develo pment of longitudinal cracks parallel to the loading direction. This i ncreased the amount of damage and ultimately led to total specimen fai lure prematurely. The larger the magnitude of the compression cycle, t he earlier the development of longitudinal crack occurred and, consequ ently, the earlier failure occurred. This behavior was due to the inhe rently poor interfacial bond between matrix and fiber of the tested ce ramic matrix composite.